1. Field of the Invention
The present invention relates to a liquid crystal display (“LCD”) panel and a method of manufacturing the LCD panel. More particularly, the present invention relates to an LCD panel and a method of manufacturing the LCD panel capable of reducing or preventing metal erosion due to crack generation by a conductive dot.
2. Description of the Related Art
Recently, CRTs (Cathode Ray Tubes) are most widely used as display devices. However, since CRTs have the difficulty in implementing slim, light products, alternative display types have been developed and used. These display types include flat panel displays (“FPDs”) such as liquid crystal displays (“LCDs”), plasma display panels (“PDPs”), organic light emitting diodes (“OLED”), and other types of flat panel displays. Of these display types, LCDs, which have low power consumption, high resolution, and a large display area, are the most widely used.
LCDs display an image by adjusting light transmittance of a liquid crystal using an electric field. Generally, LCDs include a color filter substrate and a thin film transistor substrate opposing the color filter substrate, with the liquid crystal interposed therebetween.
The color filter substrate includes, as an upper substrate, a black matrix for preventing light leakage, color filters for implementing colors (usually red, green, and blue), and a common electrode for applying a common voltage to the liquid crystal.
The thin film transistor substrate includes, as a lower substrate, gate lines and data lines crossing the gate lines, thin film transistors each formed in pixel regions defined by adjacent crossing gate and data lines, and pixel electrodes connected to the thin film transistors. Additionally, a conductive dot for supplying the common electrode with a common voltage is formed between the thin film transistor substrate and the color filter substrate. A common voltage supplying pad which delivers the common voltage supplied from an external power source is formed on the thin film transistor substrate, as is a contact electrode portion connected to the common voltage supplying pad and the conductive dot.
The contact electrode portion is connected to the common voltage supplying pad, and includes a first contact electrode formed under an insulating layer and a second contact electrode connected to the first contact electrode through a contact hole that penetrates the insulating layer. The conductive dot is formed on the second contact electrode. In order to reduce contact resistances of the first contact electrode and the second contact electrode, the contact hole is formed to have an area greater than a cross-sectional area of the conductive dot.
Because of the pressure of the conductive dot, a crack may be generated on the second contact electrode. Moisture can then penetrate into the first contact electrode through the generated crack, thereby eroding the first contact electrode. In particular, if the first contact electrode is formed using aluminum or an aluminum alloy, etc. a serious erosion problem may occur.